#######################################################
# GRAPHICS:
#######################################################

# see link: http://www.kosbie.net/cmu/spring-13/15-112/

#######################################################
# ANIMATIONS:
#######################################################

# Elements of an Event-Based Program:
# 1) run()
#	creates canvas and canvas.data; registers event handlers; calls init; starts timer; etc
#	You call run() to start program
# 2) init()
#	initialize values in canvas.data
# 3) mousePressed(event)
#	extract mouse location via event.x, event.y
#	modify canvas.data based on mouse press location
#	call redrawAll if view changed
# 4) keyPressed(event)
#	extract char and/or keysym from event.char and event.keysym
#	modify canvas.data based on key pressed
#	call redrawAll if view changed
# 5) timerFired()
#	modify canvas.data based on elapsed time
#	call redrawAll if view changed
#	all canvas.after() to schedule next timerFired event (after a delay of your choice)
# 6) redrawAll()
#	clear the canvas with canvas.delete(ALL)
#	redraw all canvas elements from back to front based on values in canvas.data

# -----> see kesden.zip online for recitation example!!!

#######################################################
# FUNCTIONS AS ARGUMENTS/FUNCTIONS IN FUNCTIONS:
#######################################################

# given this:
def done(value):
	print "DONE!"
	return (value / 10)

def one(x, func):
	print "one!"
	x += 1
	def two(y):
		print "two!"
		y += 1
		if not (y % 10):
			print "found it!"
			return True
		return False
	test = two(x)
	if test:
		def three(z):
			print "three!"
			return (z + 1)
		x = three(x)
	else:
		def four(z):
			print "four!"
			return 0
		x = four(x)
	return func(x)

# what will the following print?
# return one(18) # why is this wrong???
print one(18, done)
print
print one(10, done)

#######################################################
# FUNCTIONS WRAPPERS (A.K.A. CONTRACTS):
#######################################################

# given this:
def contract(func):
	def check(x, s):
		if (x < 0) or (x >= len(s)): 
			print "index must be positive and within string!"
			return
		else:
			return func(x, s)
	return check

@contract
def printIndex(x, s):
	return s[x]

# what will the following print?
print
print printIndex(0, "abcd")
print printIndex(-1, "abcd")
print printIndex(12, "abcd")
print

#######################################################
# ARGUMENT LISTS:
#######################################################
# *args -> take all arguements and pass in as a list
#					OR
#		-> take a list of arguements and make them
#		   into individual arguemnts

def func_1(*args):
	final = ""
	for s in args:
		final += s
	print final

func_1("hey ", "there ", "buddy!")

def func_2(a, b, c, d):
	if ((a + b + c + d) <= 10) and \
		(a > 0) and (b > 0) and (c > 0) and (d > 0):
			return a + b + c + d
	else:
		return "invalid input"

test = [1, 2, 3, 4]
print func_2(*test)
test.remove(1)
test.append(4)
print func_2(*test)